SEEG-guided radiofrequency thermocoagulation (SEEG-RFTC) uses electrodes already implanted for stereoelectroencephalography to create small controlled thermal lesions within selected parts of an epileptogenic network.
It can provide treatment during the same invasive evaluation used to localise seizures.
How it works
Radiofrequency current is passed between selected SEEG electrode contacts.
The resulting heat produces a small area of coagulative tissue injury around the contacts.
Why SEEG is needed first
The treatment target is chosen from the electroclinical information collected during SEEG.
RFTC therefore depends on a well-defined seizure-onset network rather than simply ablating an abnormal MRI area.
Who may be considered?
SEEG-RFTC may be considered when seizures arise from a relatively compact network sampled by the implanted electrodes, particularly when conventional resection would be difficult or more invasive.
Reported applications include periventricular nodular heterotopia, focal cortical dysplasia, hypothalamic hamartoma and selected mesial temporal epilepsies.
What the evidence shows
A 2025 meta-analysis found that SEEG-RFTC can produce meaningful seizure reduction and seizure freedom in selected people with drug-resistant focal epilepsy, but the evidence base is still dominated by retrospective observational studies.
Outcomes vary by pathology
Results are not uniform across all epilepsy causes.
Some series report particularly favourable outcomes in compact lesions such as periventricular nodular heterotopia and selected focal cortical dysplasias.
Standard versus cross-electrode RFTC
Traditional RFTC typically creates lesions between contacts on the same electrode.
Newer cross-electrode approaches create lesions between contacts on separate electrodes, allowing a larger or more conformal treatment volume.
A 2026 review reported promising results but emphasised that this technique remains relatively new and requires further validation.
RFTC as a test of the network
Response to RFTC can sometimes provide additional information about whether the treated region is an important node in the seizure network.
Improvement after RFTC may support later resection or ablation planning.
RFTC is not equivalent to open resection
The lesions produced are much smaller than many surgical resections.
For broad epileptogenic networks, limited coagulation may reduce seizures without achieving seizure freedom.
Memory and psychiatric effects
Recent work has highlighted that mesial temporal RFTC can affect memory and mental health, particularly when larger mesial structures are treated.
“Minimally invasive” does not mean neurologically consequence-free.
Risks
Risks include haemorrhage, oedema, neurological deficit, memory change and injury to nearby structures.
The exact risk depends on target anatomy and the number and position of coagulations.
Children
A 2025 paediatric systematic review concluded that evidence remains limited but supports SEEG-guided RFTC as a reasonable option in carefully selected children with drug-resistant focal epilepsy.
The central point
SEEG-RFTC turns diagnostic electrodes into a targeted treatment tool. It can be highly useful in selected compact epileptogenic networks, but it does not replace resection or larger ablation when the seizure network is broad.
Related reading
SEEG →
Periventricular Nodular Heterotopia →
LITT →
Sources
- SEEG in 2025: progress and radiofrequency thermocoagulation
- SEEG-guided radiofrequency thermocoagulation — 2025 meta-analysis
- Cross-electrode radiofrequency thermocoagulation — 2026 review
Evidence checked: September 2026.